class MyCircularQueue {
    private int[] elem;
    private int front;
    private int rear;

    public MyCircularQueue(int k) {
        elem = new int[k + 1];
        front = 0;
        rear = 0;
    }

    public boolean enQueue(int value) {
        if (isFull()){
            return false;
        }
        elem[rear] = value;
        rear = (rear + 1) % elem.length;
        return true;
    }

    public boolean deQueue() {
        if (isEmpty()){
            return false;
        }
        front = (front + 1) % elem.length;
        return true;
    }

    public int Front() {
      if (isEmpty()){
          return -1;
      }
      return elem[front];
    }

    public int Rear() {
        if (isEmpty()){
            return -1;
        }

        // 返回队列的尾部元素
        int index = rear == 0 ? elem.length - 1 : rear - 1;
        return elem[index];
    }

    public boolean isEmpty() {
        return front == rear;
    }

    public boolean isFull() {
        return (rear + 1) % elem.length == front;
    }
}